The Entrapment and Concentration of SARS-CoV-2 Particles with Graphene Oxide: An In Vitro Assay

Previous studies have suggested that graphene oxide (GO) has some antiviral capacity against some enveloped viruses, including SARS-CoV-2. Given this background, we wanted to test the in vitro antiviral ability to GO using the viral plaque assay technique. Two-dimensional graphene oxide (GO) nanoparticles were synthesized using the modified Hummers method, varying the oxidation conditions to achieve nanoparticles between 390 and 718 nm. The antiviral activity of GO was evaluated by experimental infection and plaque formation units assay of the SARS-CoV-2 virus in VERO cells using a titrated viral clinical isolate. It was found that GO at concentrations of 400 µg/mL, 100 µg/mL, 40 µg/mL, and 4 µg/mL was not toxic to cell culture and also did not inhibit the infection of VERO cells by SARS-CoV-2. However, it was evident that GO generated a novel virus entrapment phenomenon directly proportional to its concentration in the suspension. Similarly, this effect of GO was maintained in assays performed with the Zika virus. A new application for GO nanoparticles is proposed as part of a system to trap viruses in surgical mask filters, air conditioning equipment filters, and air purifier filters, complemented with the use of viricidal agents that can destroy the trapped viruses, an application of broad interest for human beings.

Real-world efficacy of switching to bictegravir/ emtricitabine/tenofovir alafenamide in pretreated patients with triple therapy containing rilpivirine

Objetivo

Analizar la eficacia y tolerabilidad de la estrategia de cambio desde regímenes basados en rilpivirina (RPV) a bictegravir/emtricitabina/tenofovir alafenamida (B/F/TAF) en la vida real.

Métodos

Estudio unicéntrico, observacional y retrospectivo. Se seleccionaron pacientes que cambiaron de un régimen con RPV a B/F/TAF antes de febrero del 2020 analizándose los resultados después de 24 y 48 semanas. Se determinó el porcentaje que permanecía con carga viral indetectable, así como los cambios en linfocitos CD4+, parámetros metabólicos y función renal.

Resultados

Se incluyeron en el estudio 42 pacientes. 32 de los 35 (91,4%) que completaron las 48 semanas de seguimiento tenían carga viral indetectable. El recuento de linfocitos CD4+ permaneció estable a las 24 y a las 48 semanas. El tipo de análogos recibidos previamente no influyó en la respuesta

Conclusión

El cambio desde una triple terapia con RPV a B/F/TAF es una estrategia segura y eficaz en la vida real.

Systematic training in master swimmer athletes increases serum insulin growth factor-1 and decreases myostatin and irisin levels

During ageing, anabolic status is essential to prevent the decrease in quantity and quality of skeletal muscle mass (SMM). Exercise modulates endocrine markers of muscle status. We studied the differences of endocrine markers for muscle status in 62 non-sarcopenic Mexican swimmer adults aged 30-70 y/o, allocated into two groups: the systematic training (ST) group including master athletes with a physical activity level (PAL) >1.6, and the non-systematic training group (NST) composed by subjects with a PAL <1.5. Body composition, diet, biochemical and endocrine markers were analyzed. The ST group showed lower myostatin (MSTN) and irisin (IRI) levels, two strong regulators of SMM. The insulin growth factor-1 (IGF-1) was higher in the ST. This is consistent with most of the evidence in young athletes and resistance training programs, where IGF-1 and IRI seem to play a crucial role in maintaining anabolic status in master athletes.

Association of cagA+ Helicobacter pylori strains with high urease activity and dyspepsia in Mexican adults

INTRODUCTION AND AIMS

Helicobacter pylori (H. pylori) is associated with a higher risk of peptic ulcer and gastric cancer. The sole presence of the bacterium is not a determinant of clinical outcome, but rather the interaction of strain type and host factors determines the risk of disease. Our aim was to study the association between bacterial load, strain type, and gastric symptoms in H. pylori-positive subjects.

MATERIALS AND METHODS

In a community survey, a diagnostic ¹³C-urea breath test for H. pylori was performed on 302 volunteers that were not taking antibiotics, antacids, or proton pump inhibitors one month prior to the test. The breath test produced 25 H. pylori-positive subjects, between 25-74 years of age, who then took a gastric symptoms survey and were tested for the presence of the cagA genotype in gastric juice, using the Entero-test®. Bacterial load was determined as a measure of urease activity, utilizing the delta over baseline value, obtained in the ¹³C-urea breath test.

RESULTS

A total of 48% of the H. pylori-positive subjects were cagA+. A positive association was found between cagA status and high gastric urease activity (P<.0001) and the latter was significantly associated with the presence of symptoms (P<.0001).

CONCLUSION

Gastric urease activity was strongly associated with dyspeptic symptoms and cagA+ H. pylori. Elevated ¹³C-delta over baseline values could be used as indicators of a higher risk for gastric disease.

[Helicobacter pylori infection in the HIV + population: a comorbidity to think about]

Introducción

. Las alteraciones gastrointestinales, son frecuentes en VIH+. Helicobacter pylori puede ser una causa infradiagnosticada.

Material y métodos

Se realizó una búsqueda retrospectiva de pacientes VIH+ con infección por H. pylori entre enero de 1998 hasta diciembre de 2017.

Resultados

Se incluyeron 132 pacientes. La dispepsia fue la sintomatología más frecuente. Un 88,5% tuvo gastritis crónica atrófica. Se consiguió la erradicación en 102 (77,3%). La curación fue más frecuente con pauta cuádruple (p=0,004) y en los más jóvenes (p=0,041).

Conclusión

La infección por H. pylori podría ser responsable de manifestaciones digestivas inespecíficas en los pacientes VIH+.

Preparation of Chitosan/Poly(Vinyl Alcohol) Nanocomposite Films Incorporated with Oxidized Carbon Nano-Onions (Multi-Layer Fullerenes) for Tissue-Engineering Applications

Recently, tissue engineering became a very important medical alternative in patients who need to regenerate damaged or lost tissues through the use of scaffolds that support cell adhesion and proliferation. Carbon nanomaterials (carbon nanotubes, fullerenes, multi-wall fullerenes, and graphene) became a very important alternative to reinforce the mechanical, thermal, and antimicrobial properties of several biopolymers. In this work, five different formulations of chitosan/poly(vinyl alcohol)/oxidized carbon nano-onions (CS/PVA/ox-CNO) were used to prepare biodegradable scaffolds with potential biomedical applications. Film characterization consisted of Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), tension strength, Young's modulus, X-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). The degradation in a simulated body fluid (FBS) demonstrated that all the formulations lost between 75% and 80% of their weight after 15 days of treatment, but the degradation decreased with the ox-CNO content. In vivo tests after 90 days of subdermal implantation of the nanocomposite films in Wistar rats' tissue demonstrated good biocompatibility without allergenic reactions or pus formation. There was a good correlation between FBS hydrolytic degradation and degradation in vivo for all the samples, since the ox-CNO content increased the stability of the material. All these results indicate the potential of the CS/PVA/ox-CNO nanocomposite films in tissue engineering, especially for long-term applications.

[Improvement of insulin sensitivity after an intensive lifestyle program for youth's weight management in the primary care]

The aim of this study was to evaluate an intensive lifestyle intervention for weight management among youth in a primary care setting on insulin sensibility, compared to a control group. The study included 42 youths 9-17 years old (n=23 intensive lifestyle intervention, n=19 control group) who completed a randomized trial for weight management in a primary care setting which included an oral glucose tolerance test. The intensive lifestyle intervention included monthly consultations with the primary care physician, nutrition counseling with a registered dietitian (weekly first 3 months and then monthly) and 12 group sessions in a behavioral change protocol. The control group attended monthly consultations with the primary care physician. Insulin sensitivity was estimated by the Insulin Sensitivity Index ISI(0,120) at baseline and 6 months posttreatment. At 6 months, the mean +/- DE, increase in insulin sensitivity was greater in the intensive lifestyle intervention than the control group (+46.8 +/- 56 vs. +5.6 +/- 47, between-group difference 41.2 [CI 95%, 8.5, 73.9], p = 0.01): Sixty five percent of youths on the intensive lifestyle intervention increased insulin sensitivity over 9 units vs. 32% in the control group (p=0.03). This study shows preliminary evidence that an intensive lifestyle intervention program can be an alternative model to improve insulin sensitivity among youths in the primary care setting.

[Coinfection with HIV and HCV: abacavir and ribavirine, why not?]

A 48-year old male coinfected by human immunodeficiency virus and hepatitis C virus (HCV) genotype 3a. The patient was under clinically and virologically effective treatment with Trizivir (zidovudine, lamivudine and abacavir) when it was decided to initiate treatment for the chronic HCV infection with peginterferon and ribavirin. Should the ongoing antiretroviral treatment be adjusted?

Prediction of fat-free mass by bioelectrical impedance analysis in older adults from developing countries: a cross-validation study using the deuterium dilution method

OBJECTIVE

Several limitations of published bioelectrical impedance analysis (BIA) equations have been reported. The aims were to develop in a multiethnic, elderly population a new prediction equation and cross-validate it along with some published BIA equations for estimating fat-free mass using deuterium oxide dilution as the reference method.

DESIGN AND SETTING

Cross-sectional study of elderly from five developing countries.

METHODS

Total body water (TBW) measured by deuterium dilution was used to determine fat-free mass (FFM) in 383 subjects. Anthropometric and BIA variables were also measured. Only 377 subjects were included for the analysis, randomly divided into development and cross-validation groups after stratified by gender. Stepwise model selection was used to generate the model and Bland Altman analysis was used to test agreement.

RESULTS

FFM = 2.95 - 3.89 (Gender) + 0.514 (Ht2/Z) + 0.090 (Waist) + 0.156 (Body weight). The model fit parameters were an R2, total F-Ratio, and the SEE of 0.88, 314.3, and 3.3, respectively. None of the published BIA equations met the criteria for agreement. The new BIA equation underestimated FFM by just 0.3 kg in the cross-validation sample. The mean of the difference between FFM by TBW and the new BIA equation were not significantly different; 95% of the differences were between the limits of agreement of -6.3 to 6.9 kg of FFM. There was no significant association between the mean of the differences and their averages (r= 0.008 and p= 0.2).

CONCLUSIONS

This new BIA equation offers a valid option compared with some of the current published BIA equations to estimate FFM in elderly subjects from five developing countries.

Impact of Giardia intestinalis on vitamin a status in schoolchildren from northwest Mexico

We conducted a cross-sectional study in northwest Mexico in order to investigate the association between giardiasis and serum vitamin A in 40 Giardia-infected and 70 Giardia-free schoolchildren who were covered by a regional school breakfast program. There were no significant differences in age, Z-scores for nutritional indices of height for age, weight for age, or weight for height, socioeconomic conditions (employment and education of the parents, household conditions, sanitation facilities, type of drinking water, and family income), and mean daily intakes of vitamin A in the Giardia-free (899 +/- 887 microg) and the Giardia-infected (711 +/- 433 microg) groups. A higher concentration of serum retinol was found in the Giardia-free group than in the Giardia-infected group (0.75 micromol/L versus 0.61 micromol/L, respectively; p < 0.0001). Giardia-infected children were more likely to be vitamin A-deficient than the Giardia-free children (OR = 3.2; 95% CI = 1.2-8.5). Although 95% of the children met the daily-recommended intakes of vitamin A, half of them showed subclinical vitamin A deficiency. It is recognized that vitamin A deficiency is multifactorial and giardiasis was a factor significantly associated with this deficiency in this study. Mexican program developers and policymakers should be aware about the distinction between dietary deficiencies and deficiency diseases when current national program strategies for parasitic control and vitamin A supplementation are redesigned.

Effect of the extrusion on functional properties and mineral dialyzability from Phaseolus vulgaris bean flour

The effects of extrusion conditions on cooking degree, flour dispersion viscosity and mineral potential availability of extruded bean flour were studied. Phaseolus vulgaris beans of the agronomic cultivar "Flor de mayo" were ground and dehulled to obtain grits and then extruded at different temperatures (140, 160 and 180 degrees C) and moisture contents (17, 20 and 23%), according to a bifactorial experimental design. Degree of cooking was estimated by water solubility (WS) and specific mechanical energy (SME). The effect of variables on WS and SME were analysed by surface response methodology. Flour dispersion viscosity and mineral availability (estimated by in vitro dialyzability), were also evaluated on selected samples. Results showed that, within the ranges of the variables used for this study, only the effect of temperature was significant on the degree of cooking. No direct correlation was observed between water solubility and SME, although a maximum value of WS corresponded to a range of SME values of 400-500 J/g was observed. Dispersion viscosity decreases as WS increases, so if high calorie density is desired, for instance in order to produce a cream soup formula, bean grits should be extruded at high temperature and as low moisture as possible, in our case 180 degrees C and 17% moisture. On the other hand, the effects of extrusion variables on iron and zinc dialyzability were not much affected.

Body composition by the four-compartment model: validity of the BOD POD for assessing body fat in mexican elderly

OBJECTIVE

The aims of this study were to validate BOD POD in a wide sample of healthy and independent Mexican elderly men and women subjects using the 4 compartment (4C) model as the reference method, and to evaluate the assumptions of the densitometric two-compartment (2C) model.

DESIGN

Cross-sectional study designed to assess body composition and validation of a method based on 2C model (BOD POD).

SETTING

Urban and rural regions of Sonora, Mexico.

SUBJECTS

Two hundred and two free-living subjects >or=60 years old were completed in this study.

METHODS

Body density and body fat were measured by the BOD POD, total body water by deuterium dilution and total body bone ash by dual energy X-ray absorptiometry. Body composition was determined using Baumgartner's equation.

RESULTS

Percent body fat by the 4C model was 31.2 and 42.5% in men and women, respectively (P<0.001). Group mean accuracy of body fat by BOD POD against that of the 4C model showed an effect of sex (P<0.001), but not the method (P=0.27). Results of individual accuracy showed no significant difference with the identity line and the slope was significantly different from zero or a slope similar to one. Precision assessed by model R (2) was high for all subjects and for men and women by separate. The standard error of the estimate was low for all and for men and women by separate. Bland and Altman analysis showed no significant bias.

CONCLUSION

The BOD POD technique is a valid and reliable method compared to the 4C model and it could be applied in subjects with similar physical and anthropometric characteristics to subjects of this study.

Reduction in liver-related hospital admissions and deaths in HIV-infected patients since the year 2002

Since the advent of highly active antiretroviral therapy (HAART), complications of chronic liver disease (CLD) have emerged as one of the leading causes of hospital admission and death among HIV-infected patients with chronic hepatitis B virus (HBV) and/or hepatitis C virus (HCV) infections. The impact of CLD on hospital admissions and deaths in HIV-infected patients attended at one reference HIV hospital in Madrid during the last 9 years was analysed. All clinical charts from January 1996 to December 2004 were retrospectively examined. Demographics, discharge diagnosis, complications during inhospital stay and causes of death were recorded. A total of 2527 hospital admissions in 2008 distinct HIV-infected persons were recorded. Overall, 84% were iv drug users; mean age was 37 years and the mean CD4 count was 224 cells/muL. Both mean age and CD4 count significantly increased during the study period (P < 0.01). Overall, 42% of hospitalized patients were on antiretroviral therapy. Decompensated CLD was the cause of admission and/or developed during hospitalization in 345 patients (14%). Admissions caused by decompensated CLD increased significantly from 9.1% (30/329) in 1996 to 26% (78/294) in 2002. A significant steady decline occurred since then, being 11% (29/253) in the year 2004. Similarly, inhospital liver-related deaths were 9% (5/54) in 1996, peaked to 59% (10/17) in 2001 and declined to 20% (3/15) in the year 2004. Chronic hepatitis C was responsible for admissions and/or deaths in 73.5% of CLD cases. In conclusion, the rate of liver-related hospital admissions and deaths among HIV-infected patients peaked in the year 2002 and has steadily declined since then. A slower progression to liver cirrhosis in patients on HAART, avoidance of hepatotoxic antiretroviral drugs and more frequent use of anti-HCV therapy in HIV/HCV-coinfected patients could account for this benefit.

Total energy expenditure, resting metabolic rate and physical activity level in free-living rural elderly men and women from Cuba, Chile and México

OBJECTIVE

The objective of this study was to assess total energy expenditure (TEE), resting metabolic rate (RMR) and physical activity level (PAL), and to estimate energy requirements (ERs) in free-living elderly subjects from Cuba, Chile and Mexico.

DESIGN

Cross-sectional study designed to estimate ERs.

SETTING

Rural regions of Cuba, Chile and Mexico.

SUBJECTS

Forty subjects >60 years old were selected to participate in this study.

INTERVENTIONS

A dose of doubly labeled water (DLW) was administered and urine samples were collected in the following 12-14 days. From the isotopic analysis, TEE was derived. RMR was measured by indirect calorimetry.

RESULTS

TEE in Chilean (8.8+/-1.6 MJ/day) and Cuban (8.3+/-1.3 MJ/day) elderly was not different, and was higher for the Mexican group (9.5+/-1.5 MJ/day) (P < 0.0001). RMR was not different between countries. PAL and activity energy expenditure (AEE) were only different between Chile and Mexico (P < 0.002). For the three regions, overall PALs were 1.70+/-0.16 for male and 1.62+/-0.13 for female subjects (P < 0.02), and AEE was 3.05+/-0.66 and 2.27+/-0.66 MJ/day for male and female subjects, respectively (P < 0.001). Predictive equations (MJ/day) were RMR = 1.6447 + 0.05714 x weight (kg) + 0.449 sex (male = 1; female = 0) (R2 = 0.75; SEE = 0.479) and TEE = 3.414 + 0.0795 x weight (kg) + 1.227 x sex (male = 1; female = 0) (R2 = 0.75; SEE = 0.668).

CONCLUSIONS

There were differences in TEE and PAL owing to sex and region. The average PAL in men was higher than the PAL reported either with factorial approach or with the DLW method in elderly. Predictive ER equations based on RMR and TEE gave very similar results to calculations from the 2004 FAO/WHO/UNU report.

Prevalence and intensity of intestinal parasitic infections in relation to nutritional status in Mexican schoolchildren

Undernutrition and intestinal parasitic infections affect childhood development and morbidity in many developing countries. Undernutrition may increase susceptibility to parasitic infections which in turn impair the nutritional status of the host. The relationship between intestinal parasitic infections and nutritional status in 400 Mexican schoolchildren was investigated. More than half of the children in the study showed intestinal parasites and polyparasitism. The prevalence of helminth infections was significantly higher in Oaxaca than in Sinaloa (P < 0.05). Z scores for weight-for-age (WA) and height-for-age (HA) were much lower in children of Oaxaca than in Sinaloa (P < 0.001). A significantly higher Z score for weight-for-height (WH), WA, and HA were found in non-infected versus infected children (P < 0.05). Higher prevalences of intestinal infections were found in children with lower HA and WA than in normally nourished children (P < 0.05). Higher intensities of Ascaris lumbricoides and Trichuris trichiura were found in the schoolchildren of Sinaloa than in Oaxaca (P < 0.01). Negative and significant associations were found between Hymenolepis nana and T. trichiura infection (eggs per gram) and nutritional status. Intestinal parasitic infections may be regarded as main risk factors associated with poor nutritional status in Mexican schoolchildren.

The usefulness of stable isotopes in nutrition and human health: the application of mass spectrometry and 13C-breath tests to detect helicobacter pylori infection

The interest in Helicobacter pylori has escalated in recent years. H. pylori may produce a chronic gastric infection which is usually life-long and many epidemiological studies have shown that this is the most common bacterial infection throughout the world involving 50% of the world population. Thus, it is clear that the diagnosis of H. pylori infection represents at least a key step in the management of many of the patients referred to the gastroenterologist. Additionally, due to the wide range and relevance of pathologies possibly related to this infection, from micronutrient malnutrition and co-infections to malignancies, there is the potential for H. pylori to be a major health problem. Improved methods for the diagnosis and follow up treatment of the infection have been developed. Use of stable isotopes as non-invasive and safe diagnostic methods, namely (13C) breath tests, has been the key to a new era of research in H. pylori epidemiology and diagnosis as well as the establishment of eradication therapies. This non-invasive nuclear technique, that is considered the gold standard for the diagnosis of this bacterial infection, has successfully been standardized and implemented along Latin America. Taking into account the high prevalence of this bacterial infection, the impact of this technique in the whole region is very high. In this article we discuss several aspects of this methodology in order to harmonize the application of this method in developing regions.

Determination of body composition using air displacement plethysmography, anthropometry and bio-electrical impedance in rural elderly Mexican men and women

BACKGROUND AND AIMS

Air displacement plethysmography with the BOD-POD is a new densitometry technique, and has been found to be an accurate method to measure body composition. The aim of this study was to assess body composition in a group of free living healthy subjects 60 years of age or older from a rural area of Northwest Mexico, and to evaluate body composition by anthropometry and bioelectrical impedance (BIA) using equations reported for other elderly populations.

METHODS

Body composition was evaluated in 21 women and 26 men with the BOD-POD, by anthropometry, and BIA and compared to different equations using the Bland- Altman procedure.

RESULTS

Body fat in elderly women and men was 42.7 and 30.2 % respectively. In women, Segal's equation using BIA 1, based on standing height, showed no significant differences with the BOD-POD. There was satisfactory agreement between Segal's equation and BOD-POD. In men similar results was found with Deurenberg's equation using B1A 2 based on recumbent length.

CONCLUSIONS

Segal's and Deurenberg's equations were accurate and precise for the estimation of body fat in the elderly of this study. The use of these equations could improve the estimation of body composition for similar elderly subjects. Further studies are recommended with a larger size samples to include elderly subjects from other Latin American countries.

Estimation of body fatness from body mass index and bioelectrical impedance: comparison of New Zealand European, Maori and Pacific Island children

OBJECTIVE

To compare percentage body fat (%BF) for a given body mass index (BMI) among New Zealand European, Maori and Pacific Island children. To develop prediction equations based on bioimpedance measurements for the estimation of fat-free mass (FFM) appropriate to children in these three ethnic groups.

DESIGN

Cross-sectional study. Purposive sampling of schoolchildren aimed at recruiting three children of each sex and ethnicity for each year of age. Double cross-validation of FFM prediction equations developed by multiple regression.

SETTING

Local schools in Auckland.

SUBJECTS

Healthy European, Maori and Pacific Island children (n=172, 83 M, 89 F, mean age 9.4+/-2.8(s.d.), range 5-14 y).

MEASUREMENTS

Height, weight, age, sex and ethnicity were recorded. FFM was derived from measurements of total body water by deuterium dilution and resistance and reactance were measured by bioimpedance analysis.

RESULTS

For fixed BMI, the Maori and Pacific Island girls averaged 3.7% lower %BF than European girls. For boys a similar relation was not found since BMI did not significantly influence %BF of European boys (P=0.18). Based on bioimpedance measurements a single prediction equation was developed for all children: FFM (kg)=0.622 height (cm)(2)/resistance+0.234 weight (kg)+1.166, R(2)=0.96, s.e.e.=2.44 kg. Ethnicity, age and sex were not significant predictors.

CONCLUSIONS

A robust equation for estimation of FFM in New Zealand European, Maori and Pacific Island children in the 5-14 y age range that is more suitable than BMI for the determination of body fatness in field studies has been developed.

Body composition by hydrometry (deuterium oxide dilution) and bioelectrical impedance in subjects aged >60 y from rural regions of Cuba, Chile and Mexico

BACKGROUND

In Latin American and Caribbean countries such as Chile, Mexico and Cuba, the population over 60 y has increased steadily. In this age group, there is scarce information about body composition, particularly for those living in rural areas.

OBJECTIVE

The purpose of this study was to determine body composition in free-living and healthy elderly subjects >60 y from rural areas of Chile, Cuba and Mexico using deuterium oxide dilution and bioelectrical impedance (BIA) and to develop and cross-validate a predictive equation for this group of subjects by BIA for future use as a field technique.

SUBJECTS

The study included 133 healthy subjects (73 males and 60 females) >60 y from rural regions of Cuba, Chile and Mexico.

MEASUREMENTS

Total body water, body weight, height and other anthropometric and BIA variables (resistance and reactance) were measured.

METHODS

Total body water was determined by deuterium oxide dilution, and fat-free mass (FFM)/fat mass were derived from this measurement. The total sample was used in a split-sample internal cross-validation. BIA and other anthropometric variables were integrated to multiple regression model to design the best predictive equation, which was validated in the other sample. ANOVA, multiple regression and Bland and Altman's procedure were used to analyze the data.

RESULTS

Body weight, percentage of fat and fat-free mass were lower in the Cuban men and women compared with Chilean and Mexican men and women. The best predictive equation of the FFM was: FFM kg=(-7.71+(H(2)/R x 0.49)+(country or ethnicity x 1.12)+(body weight x 0.27)+(sex x 3.49)+(Xc x 0.13)), where H(2) is height(2) (cm); R is resistance (Omega); country: Chile=1, Mexico=2 and Cuba=3; sex: women=0 and men=1; body weight (kg) and Xc is reactance (Omega). R(2) was 0.944 and the root mean square error (RMSE) was 2.08 kg. The mean+/-s.d. of FFM prediction was 44.2+/-9.2 vs 44.6+/-10.1. The results of cross-validation showed no significant difference with the line of identity, showing that the predicted equation was accurate. The intercept (=-0.32) was not significantly different from zero (P=0.89) and the slope (=1.02) not significantly different from 1.0 (P>0.9). The R(2) was 0.86, RMSE=3.86 kg of FFM and the pure error was 3.83.

CONCLUSION

The new BIA equation is accurate, precise and showed good agreement. The use of this equation could improve the estimates of body composition for the elderly population for these regions, as well as enhancing the opportunity to conduct studies in the elderly population from Latin America.

Measuring the intakes of foods and nutrients of marginal populations in north-west Mexico

OBJECTIVE

To describe methodological issues regarding the measurement of food intake of marginal populations in the north-west of Mexico.

METHODS

Dietary data from three sources were analysed. The Sonora State Food Basket Study (505 individuals from all ages, both sexes, high, medium and low income, and from urban and rural settings), 144 individuals from rural Indian communities, and 152 low-income urban women. Methods of dietary data collection were single 24-hour recalls for the first two studies, and four non-consecutive 24-hour recalls as well as a food-frequency questionnaire (FFQ) for low-income urban women.

RESULTS

The food patterns in the three studies showed similar core foods; however, food diversity resulted in 19, 13 and 57 different foods reported by 90% of the population in the state, Indian communities and urban women, respectively. Mean intakes of selected food components in the sample of urban women vs. a representative sample of the population of the state were similar, although smaller variation in consumption was observed in urban women with repeated 24-hour recalls. Inter-individual variation in intake of food components was similar in the state and urban women samples, but the Indian communities showed lower coefficients of variation (CVs). Use of four 24-hour recalls decreased the inter-individual variation in food component intakes of low-income urban women, especially for vitamin intakes. The FFQ did not show an additional decrease in inter-individual variation for macronutrients, but reduced even more the CVs for vitamins. Intra-individual variation was higher than inter-individual variation for urban women's intakes when estimated by repeated 24-hour recalls. This effect was reversed when estimated by duplicate food frequencies. Ratios of intra-individual to inter-individual variation in food intake were lower for Mexican when compared with US women. These results should be considered, especially for association analysis of low-income women's diets and health outcomes.

Dietary fiber and lifestyle influence serum lipids in free living adult men

OBJECTIVE

The aim of this study was to determine the effect of dietary fiber consumption and lifestyle on serum lipids in adult men with non-restricted diet and physical activity.

METHODS

Two groups of 19 men were classified as high (48 g/day) and low fiber groups (27 g/day). Anthropometry, food frequency, daily weighed intakes and physical activity were done for a seven-day period. Fasting blood was collected and serum was analyzed for triglycerides, total cholesterol and lipoprotein cholesterol fractions.

RESULTS

Crude correlation coefficients showed that total cholesterol was negatively associated with physical activity, total dietary fiber and P/S ratio (r = 0.52; p < 0.001. r = -0.44; p < 0.01, r = 0.51, p < 0.001). LDL-C was also correlated negatively with total dietary fiber and P/S ratio (r = -0.34, p < 0.03; r = -0.53, p < 0.01). It was also positively associated with dietary cholesterol and body weight (r = 0.34, p < 0.03; r = 0.31, p < 0.05). Serum triglycerides had an inverse association with total dietary fiber and physical activity (r = -0.30: p < 0.05; r = -0.45, p < 0.004). After controlling for energy intake, total fat, saturated fat, dietary cholesterol, physical activity and body mass index, LDL-C/HDL-C, and TC/HDL-C, remained significantly associated with dietary fiber (r = 0.34; p < 0.05 and r = -0.38; p < 0.02, respectively).

CONCLUSIONS

This study provides evidence in free living men that there is an association between dietary fiber intake and favorable lipid status and that lifestyle defined by socioeconomic status, physical activity and the quality of the dietary fat intake can play an important role. Public health nutrition advice and policy should continue to emphasize the importance of these factors.

Response to liposomal doxorubicin and clinical outcome of HIV-1-infected patients with Kaposi's sarcoma receiving highly active antiretroviral therapy

PURPOSE

HIV-associated Kaposi's sarcoma (KS) may not resolve despite highly active antiretroviral therapy (HAART). Moreover, the therapeutic goal has shifted from palliative care to long-term durable complete remission. The objective of the study was to assess the impact of liposomal doxorubicin in the treatment of HIV-associated KS in the HAART era.

METHOD

In this prospective, noncomparative, multicenter study, patients with more than 10 cutaneous lesions or visceral disease were treated with 20 mg/m(2) of liposomal doxorubicin (Caelyx) every 3 weeks in addition to their antiretroviral therapy. In addition to tumor measurements and laboratory tests, human herpes virus 8 (HHV-8) polymerase chain reaction (PCR) in peripheral blood mononuclear cells (PBMC) was performed.

RESULTS

Out of 79 participants enrolled in the study, 47 (59%) had stage T(1), 41 (52%) I(1), and 32 (40%) S(1). Nine individuals were not evaluable for response, 32 (40%) had complete response, 30 (38%) partial response, 5 (6%) stable disease, and 3 (4%) progression. Regression analysis did not find any statistically significant factor predicting response. HHV-8 PCR was positive in 37/53 (70%) patients with available PBMC samples, and HHV-8 viremia cleared in 14/27 (52%) without correlation with clinical response. Eleven (14%) participants experienced a relapse of KS, while at the last update of data, 49 (62%) remained stable. The only risk factor for recurrence identified was the follow-up time (odds ratio [OR] 1.21, 95% CI 1.07-1.36; p =.002).

CONCLUSION

The response rate of AIDS-associated KS to liposomal doxorubicin administered with HAART was high, and most often the response was durable. HHV-8 viremia did not correlate well with clinical outcome.

Protein quality evaluation in rats of typical diets for 4- to 6-year-old children from different socioeconomic areas living in Oaxaca, Mexico

Legumes and cereals are principal sources of energy and protein in developing countries. In Oaxaca, Mexico, corn is the primary agricultural crop, therefore corn tortillas and beans are the main energy and protein sources. The objective of this study was to evaluate the protein quality in rats of typical diets for 4- to 6-year-old children from different socioeconomic areas in Oaxaca, Mexico. Composite diets representing the typical diets were formulated and fed to male weanling rats for 10 days. A control diet using casein as the reference diet and one free of nitrogen were included in the study. The apparent protein digestibility was determined in rats using the chromic oxide marker technique and the data was statistically analyzed for differences between control and experimental diets. Rats fed the diet of low income children gained about 2 g/day compared to about 3.8 g/day for the rats fed the control (casein) diet and had the lowest weight gain/g of protein intake. The NPR was 3.52 compared to 4.31 for the control diet. This diet is 67% vegetable protein and 33% animal protein. The diet for the medium income group contained a higher percentage of animal protein, 76% and thus higher digestibility, 78%. The results of this study indicate that the protein quality of children's diets in Oaxaca, Mexico, need to be improved.

Diagnostic utility of a multiplex herpesvirus PCR assay performed with cerebrospinal fluid from human immunodeficiency virus-infected patients with neurological disorders

We used a multiplex nested-PCR assay for the simultaneous detection in cerebrospinal fluid (CSF) of five human herpesviruses (HVs) (cytomegalovirus [CMV], Epstein-Barr virus [EBV], varicella-zoster virus [VZV], herpes simplex virus [HSV], and human herpesvirus 6 [HHV-6]) in a clinical evaluation of human immunodeficiency virus (HIV)-infected patients with neurological disorders. This method, which has the advantages of being rapid and economical, would be of particular interest for the diagnosis of neurological syndromes caused by more than one HV. We studied 251 CSF samples from 219 patients. HV DNA was demonstrated in 93 (37%) of the CSF samples (34% of the patients). CMV was the HV most frequently detected in our patients (25%), while EBV, VZV, HSV, and HHV-6 DNAs were present in significantly fewer cases (7, 4, 3, and 1%, respectively). When results were compared with the final etiological diagnoses of the patients, the multiplex HV PCR showed high specificity for the diagnosis of CMV and VZV neurological diseases and for cerebral lymphoma (0.95, 0.97, and 0.99, respectively). The sensitivity of the assay was high for CMV disease (0.87), was low for cerebral lymphoma (0.33), and was not evaluable for VZV disease due to the small number of patients with this diagnosis. Nevertheless, detection of VZV DNA had possible diagnostic value in four of the nine cases, and EBV DNA amplification always predicted the diagnosis of cerebral lymphoma in patients with cerebral masses. Detection of HSV DNA was frequently associated with CMV amplification and fatal encephalitis. HHV-6 was not considered to have a pathogenetic role in the three cases in which it was detected. This multiplex HV PCR assay is a specific and clinically useful method for the evaluation of HIV-infected patients with neurological disorders related to HV.

Daily energy expenditure in Mexican and USA Pima indians: low physical activity as a possible cause of obesity

BACKGROUND

Obesity is caused by an imbalance between energy intake and energy expenditure. However, it is unknown whether increased physical activity protects susceptible populations against the development of obesity and type 2 diabetes.

OBJECTIVE

To investigate the potential protective role of environment and physical activity against obesity by measuring total energy expenditure in Mexican and USA Pima Indians.

METHODS

We compared the physical activity level of 40 (17 female and 23 male; 37+/-11 y, 66+/-13 kg) Mexican Pima Indians from a remote, mountainous area of Northwest Mexico, with 40 age-and-sex matched (17 female and 23 male; 37+/-12 y, 93+/-22 kg) Pima Indians from the Gila River Indian Community in Arizona, USA. We measured total energy expenditure (TEE) by doubly labeled water and calculated physical activity by different methods: physical activity level (PAL) as the ratio of TEE on resting metabolic rate (RMR), TEE adjusted for RMR by linear regression, activity energy expenditure adjusted for body weight (AEE), and activity questionnaire.

RESULTS

Physical activity was higher in Mexican Pima Indians when compared with USA Pima Indians as assessed by PAL (1.97+/-0.34 vs 1.57+/-0.16, P<0.0001), TEE adjusted for RMR (3289+/-454 vs 2671+/-454 kcal/day, P<0.0001) and AEE adjusted for body weight (1243+/-415 vs 711+/-415 kcal/day, P<0. 0001). Questionnaires revealed more time spent on occupational activities among Mexican Pima compared with USA Pima (23.9+/-13.3 vs 12.6+/-13.9 h/week, P<0.001).

CONCLUSION

These data support a significant role for physical activity in the prevention of obesity in genetically susceptible populations. International Journal of Obesity (2000)24, 55-59

Vitamin A deficiency and low prevalence of anemia in Yaqui Indian children in northwest Mexico

A study of 296 school-age Yaqui Indian children (6-10 y) was conducted in 26 rural communities. Vitamin A status was determined by retinol and carotenoid serum levels according to a method described previously (IVACG, 1982). Serum retinol and carotenoids in children were analyzed according to community size. Vitamin A intake was assessed in a sub-sample by means of a 24 h recall questionnaire. Serum retinol distribution showed that 6.3% of the children were below 10 microg/100 mL (0.35 micromol/L) and 40% were in the range of 10-20 microg/100 mL (0.35-0.70 micromol/L). Differences (p < 0.02) were found between small and large communities (Median, 95% CI): 19.2 (17.1, 20.9) microg/100 mL and 22.9 (20.3, 24.1) microg/100 mL. Serum carotenoid levels were significantly higher in large than in small and medium communities: 72 (68.2, 77.8) microg/100 mL versus 62.4 (53.3, 68.2) and 62.4 (55.7, 69.6) microg/100 mL, respectively. Food staples were wheat flour tortillas, pinto beans, corn tortillas, few animal products and scarce fresh vegetables. Mean vitamin A consumption was 244+/-29 microg RE (34.9% of the US RDA). Iron status showed that only 4 children were classified as anemic, with two of them having iron deficiency anemia. Iron deficient erythropoiesis was observed in 7.8% of the children and iron depletion only in 4.4%. The Yaqui diet seems to provide adequate amounts of iron but not of vitamin A or its precursors, which renders a vitamin A status of sub-clinical deficiency that could be considered a public health problem.

[Anthropometry and body composition in persons over 60. The importance of physical activity]

OBJECTIVE

To measure anthropometric indicators of body composition by electric bioimpedence, as well as physical activity, blood glucose and arterial pressure in rural people over 60 years of age.

MATERIAL AND METHODS

A total of 54 subjects over 60 years old were selected by intentional non-probabilistic sampling. They were subjected to a standardized protocol to measure anthropometric indicators, body composition by electric bioimpedance (EBI), and physical activity was determined by an activity questionnaire. Arterial pressure and glucose tolerance levels were also measured. Analysis included Student's t test to detect differences by sex and the association of physical activity, body composition and other variables by simple linear regression and Pearson's correlation coefficient.

RESULTS

Physical activity correlated negatively with percent fat (r = -0.36; p = 0.007) and diastolic (r = -0.36; p = 0.006) and systolic blood pressure (r = -0.32; p = 0.018), and body mass index with post dose glucose (r = 0.31; p = 0.024).

CONCLUSIONS

Physical activity in this age group may have a favorable impact with respect to the mentioned health indicators.

[Energy requirements in active elderly individuals living in a rural region of Northwest Mexico]

The energy requirements in free-living elderly rural people were investigated by measuring physical activity level and basal energy expenditure using a physical activity questionnaire and indirect calorimetry, respectively. Approximately 65 different occupational and leisure activities over the previous 12 months were considered. Energy expenditure by physical activity was estimated using PAL for specific activities reported in the literature. All 65 the activities were considered to adapt the questionnaire. Reproducibility was evaluated by administering the questionnaire on two separate occasions within 3-4 week elapsed between them. It was found to be reliable for the study (Pearson correlation was r = 0.85; p < 0.05). The physical activity level of the women and men were 1.50 +/- 0.29 and 1.65 +/- 0.66, respectively (p < 0.05). The basal metabolic rate also differed between women and men (p < 0.05) with 5348 +/- 719 kJ/day and 6160 +/- 862 kJ/day, respectively. Similarly the total energy expenditure was different (p < 0.05) in women and men 8311 +/- 1610 kJ/day and 10,210 +/- 2268 kJ/day, respectively. Results indicate that the physical activity questionnaire presented can be an alternative methodology to estimate physical activity in free-living elderly people and together with indirect calorimetry measurements can be useful to estimate their energy expenditure and hence energy requirements.

Plasma leptin concentrations in Pima Indians living in drastically different environments

OBJECTIVE

Plasma leptin, an important signal for the regulation of energy stores, is known to be influenced by many hormonal factors, but may also be affected by behavioral and environmental factors. The purpose of this study was to investigate the impact of lifestyle (diet composition, level of physical activity) on plasma leptin concentrations among Pima Indians living in drastically different environments.

RESEARCH DESIGN AND METHODS

We studied 224 Mexican Pima Indians (115 women, 109 men) living a traditional lifestyle in a remote, mountainous area of northwest Mexico and 418 U.S. Pima Indians (281 women, 137 men) living a North American lifestyle on the Gila River Indian Reservation in Arizona. We hypothesized that the absolute value of leptin would be lower in Mexican Pima Indians because of their lower percent body fat, but could be further influenced by their lifestyle, independent of body composition.

RESULTS

Leptin concentration (enzyme-linked immunosorbent assay [ELISA]) was strongly correlated with percent fat (bioimpedance) in Mexican Pima Indians (r = 0.83, P < 0.0001) and U.S. Pima Indians (r = 0.86, P < 0.0001). Among U.S. Pima Indians, independent of percent fat, subjects with type 2 diabetes had lower leptin than nondiabetic subjects (difference = 6.9 +/- 1.0 ng/ml, P < 0.002). Among nondiabetic subjects, Mexican Pima Indians had lower absolute leptin concentrations than U.S. Pima Indians, but higher after adjustment for percent body fat, waist circumference, age, and sex. In a subset of 70 pairs of subjects matched for sex and percent body fat, leptin concentration was 4.4 +/- 1.0 ng/ml (P < 0.0001) higher in Mexican Pima Indians versus U.S. Pima Indians.

CONCLUSIONS

These results suggest that independent of body composition, leptin concentration may be increased by environmental factors, such as a high-carbohydrate diet and a high level of physical activity.

Is a low leptin concentration, a low resting metabolic rate, or both the expression of the "thrifty genotype"? Results from Mexican Pima Indians

BACKGROUND

The high prevalence of obesity and type 2 diabetes in some populations is believed to be the expression of a "thrifty genotype," which conferred survival advantages during periods of harsh environmental conditions, but has become a liability in industrialized environments of abundance. Low plasma leptin concentrations and a low metabolic rate may be the phenotypic expression of this genotype.

OBJECTIVE

We hypothesized that plasma leptin concentrations and resting metabolic rate would be lower in Mexican Pima Indians not yet exposed to an affluent lifestyle than in non-Pima Mexicans living in the same environment.

DESIGN

We studied 208 nondiabetic Pima Indians (105 women and 103 men) living a traditional lifestyle in a remote, mountainous area of northwest Mexico and 183 nondiabetic non-Pima Mexicans (90 women and 93 men) living in the same environment. A subset of 40 (17 women and 23 men) Pima Indians and 40 (19 women and 21 men) non-Pima Mexicans was selected for studies of energy metabolism with a ventilated-hood system.

RESULTS

Leptin concentrations were strongly correlated with percentage body fat in both groups (r = 0.83, P < 0.0001). There was no significant difference in plasma leptin concentration between groups in absolute value (P = 0.90) or after adjustment for percentage body fat, waist circumference, age, and sex (P = 0.40). Similarly, there was no significant difference in resting metabolic rate between groups in absolute value (P = 0.27) or after adjustment for fat-free mass (P = 0.32).

CONCLUSIONS

These results do not support the hypothesis that hypoleptinemia, a relatively low resting metabolic rate, or both are expressions of the thrifty genotype.

[Effect of supplementation with a massive dose of vitamin A in children 6 to 36 months of age]

OBJECTIVE

To evaluate the impact of a single massive dose of vitamin A on the vitamin and iron status in children of margined urban areas in Hermosillo, Sonora, Mexico.

MATERIAL AND METHODS

A total of 60 children received one dose of 100,000 IU (children from 6 to 12 months) and of 200,000 IU (children from 12 to 36 months) of retinol palmitate distributed by the Health Ministry in June, 1994. Serum levels of retinol, carotenoids, iron, transferrin and ferritin were measured at three periods: basal, after two weeks and after three months.

RESULTS

The mean for retinol basal values was 0.7 mumol/l, after two weeks it was 0.97 mumol/l (p < 0.001) and after three months it was 0.83 mumol/l (p > 0.05). When basal values were measured, 6.3% of the children showed severe vitamin A deficiency, which disappeared in the periods following the supplement; additionally, 42% showed moderate deficiency which had decreased to less than 7% after three months. No differences were found for serum iron and transferrin levels (p > 0.05), however, ferritin levels increased (p < 0.001) after three months indicating an improvement in iron reserves.

CONCLUSIONS

Massive dose distribution may have an important impact on vitamin A and iron status in children.

Visceral leishmaniasis in patients infected with the human immunodeficiency virus

The experience with 52 episodes of visceral leishmaniasis diagnosed in 43 patients is reported. The most common symptoms were fever (81%), splenomegaly (65%), hepatomegaly (63%), and pancytopenia (73%). In 79% of the patients, CD4+ cell counts were < 100 cells/mm3. Prior or simultaneous diagnosis of AIDS was made in 29 (67%) patients. Diagnosis was considered fortuitous in 19% of the episodes. In 27% of the episodes, the diagnosis was made on the basis of demonstration of parasites outside the reticuloendothelial system, chiefly blood (7 cases) and gastrointestinal mucosa (5 cases). Parasites were frequently observed or cultured from blood (22/37 episodes) or the digestive tract (8/9 episodes). High antimony doses were more effective than low doses in achieving clinical or parasitological cure (rate of cure, 80% vs. 40%, p = 0.11). Severe toxicity was observed in six (11.7%) of the 51 treated episodes. Severe AIDS-related diseases [odds ratio (OR) 10, p < 0.05] and CD4+ counts (OR 12, p < 0.05) were independent factors for early death. Prophylaxis with monthly pentamidine was not useful in reducing relapses of visceral leishmaniasis.

[Tuberculous hepatosplenic abscess, human immunodeficiency virus infection and multiresistant tuberculosis]

BACKGROUND

Tuberculosis (TB) with liver and/or spleen abscess (HSA) formation in HIV-positive patients is uncommon.

PATIENTS AND METHODS

One hundred and thirty-seven HIV positive patients with TB were studied from January 93 to June 95. Patients with tuberculous HSA were enrolled in the study. Diagnosis was obtained by recovery of Mycobacterium tuberculosis in clinical specimens and the presence of hypoechogenic lesions in liver and/or spleen.

RESULTS

M. tuberculosis isolates were resistant to some of the usual drugs in 51 patients. Twenty of these patients had HSA (39%) and in 18 patients the antibiotic sensitivity testing showed resistance to isoniazid, rifampin, ethambutol, and streptomycin. The remaining 86 patients had episodes of TB with drug-susceptible microorganism and only three patients had HSA (3%) (p < 0.001). The 23 patients with tuberculous HSA had a mean CD4+ lymphocyte count of 33 x 10(6) cells/L (2-111) and 7 had a previous episode of TB. The abdominal echography showed hepatosplenomegaly in all cases. Abscesses were located at the liver in 12 patients (52%), spleen in 18 (78%) and both organs in 7 (30%). In 16 cases a corticosteroid therapy was indicated. In the 3 patients with susceptible TB and HSA the clinical course was good. The 20 patients with resistant TB died.

CONCLUSION

Abdominal TB in HIV-positive patients and HSA formation appears to be more common in severely immunosuppressed patients, with resistant TB and its mortality rate is high. The response to therapy with antituberculous drugs is slow and sometimes the administration of corticosteroids is necessary for the resolution of symptoms.

[Poor digestion of lactose. Its definition, prevalence in Mexico, and its implications in milk consumption]

We review the studies that have been carried out in Mexico related to prevalence of lactase deficiency. We also describe a study carried out in three regions of Mexico with different consumption of milk (Northern, Central & Southeastern), comprising 960 individuals of ages ranging from 1 to 99 years. They were evaluated in a double blind study in order to determine the prevalence of lactose maldigestion with habitual dosis of milk. Each subject received two treatments: a) 240 or 360 mL of intact milk according to age, and b) the same amount of milk but with the lactose hydrolyzed (> 90% hydrolyzed). The participants were classified as digesters or maldigesters of lactose using the hydrogen breath test. The prevalence of maldigesters was higher in the Central (30%) and Southeastern (22%) regions than in the Northern one (9%, p < 0.01). The prevalence increased with age from 4.5% (< 3 years), 13.6% (3 to 5.9), 20.8% (6 to 12.9), 21.8% (13 to 17.9) and 32.9% in adults. Lactose maldigestion affected consumption marginally.

[Lactose intolerance. Its definition, its prevalence in Mexico, and its implications in milk consumption]

In this document we describe some aspects of lactose and milk intolerance, discuss the results of studies carried out previously in Mexico, and report an investigation whose objective was to quantify the impact of lactose intolerance on the habitual consumption of milk in an open population. The prevalence of lactose intolerance and its effect on the consumption of milk was studied in three regions of Mexico. The design of the study was prospective, randomized, double-blind and crossover. The presence of milk intolerance was investigated in 960 subjects with ages between 6 months and 99 years who, as a function of age, received 240 or 360 mL of intact milk and the same amount of hydrolyzed milk. We quantified the consumption of milk and the presence of symptoms after ingesting the tested milk. Seven percent manifested symptoms with the intact milk but only 2% with the hydrolyzed milk (p < 0.001). The presence of symptoms in the intolerant subjects was significantly associated with a lower consumption of milk in comparison with the tolerant individuals (p < 0.001). On the other hand, the consumption of milk appeared to be only marginally associated with the intolerance and its symptoms. We conclude that lactose intolerance does not appear to be a major factor in determining milk consumption in Mexican healthy populations.

[HIV infection and lymphomatous meningitis]

Lymphomatous meningitis and lymphoma confined to the central nervous system are the most serious neurological diseases in patients with human immunodeficiency virus infection. The diagnosis is difficult and it is usually done with advanced systemic disease or when the chemotherapy is finished. During a ten month period, three patients with lymphomatous meningitis and HIV infection were diagnosed in an Infectious Diseases Unit. In one patient, was the initial clinical manifestation of Burkitt's lymphoma and in another, the diagnosis was concomitant with the neoplasm. In the last one, there was a meningeal recidiva afterwards he had received chemotherapy and, theoretically, cured his systemic lymphoma. Clinical, cytologic, immunologic and evolutive study of these three patients is done. It is discussed the meningeal prophylaxis usefulness with intrathecal chemotherapy.

[Colony-stimulating factors and HIV-related neoplasms]

OBJECTIVE

it is analyzed a group of patients with HIV related malignancy treated with myelosuppressive therapy with granulocyte colony stimulating factor (G-CSF) to study the efficacy of hematopoietic growth factors in these subjects.

PATIENTS AND METHODS

it was studied the clinical and hematological evolution of 20 patients with HIV related malignancy treated with standard dose of chemotherapy and 5 micrograms/Kg/day of G-CSF starting 24 hours after the completion of chemotherapy administration. It was done an epidemiological study and was determined haemoglobin level, and the number of leukocytes, monocytes, neutrophils, lymphocytes, CD4+ lymphocytes and platelets before and after the chemotherapy administration.

RESULTS

all of the patients were men with mean age of 37 +/- 2 years. The mean of lymphocyte CD4+ count was 17 x 10(6)/l and the tumor was the first aids manifestation in 50% of the subjects. The mean days of hospitalization was 14 +/- 3 days. As the result of the G-CSF administration, the leucocyte and the neutrophil count was statistically elevated (p < 0.01) and the platelets, the lymphocytes and the monocytes were not statistically elevated. Only one patient had a severe adverse reaction. Seventeen patients (85%) are dead, but only in 3 the cause was an infectious disease.

CONCLUSION

the use of G-CSF prophylactically can elevate the neutrophil count and avoid the apparition of febrile neutropenia in patients with HIV related malignancies.

Colon cancer in rats and diet in the Sonoran desert region of Mexico

The role of dietary fiber in colon cancer is still not clear. Epidemiological studies suggest a protective role for high fiber intake. However the data suggest that the effects of fiber must be considered in the context of the total diet and its interactions with other dietary components. The typical Sonora diet is high in dietary fiber (7.8%) and the majority of this fiber (71%) is insoluble. Comparing the incidence of colon cancer in Sonora with its neighboring state of Arizona, in 1991, Sonora reported 40 cases of colon cancer, a population of 1,823,606, compared to 1432 for Arizona (3,763,322 inhabitants). The typical regional diet was evaluated for its protective effect in the development of colon cancer in rats injected with azoxymethane, AOM. The regional diet showed a tendency to protect against colon cancer, an incidence of 45% compared to 66% for the control diet, although this effect was not significant (p = 0.15). Further studies are needed to fully evaluate the diet and certain interactive dietary factors such as fat, quantity as well as type, protein, calcium and antioxidant nutrients.

[Chemical composition, dietary fiber and mineral content of frequently consumed foods in northwest Mexico]

Nutrient composition in foods is very important specially in evaluation of nutritional status in populations. In this study the proximate composition, dietary fiber (DF) and mineral content of 15 frequently consumed foods in Northwest Mexico were determined. The procedures used were AOAC (1984) official methods, chemical-enzymatic method for DF and atomic absorption spectrophometry for minerals. Foods were grouped into cereals, legumes, meat and dairy products, fat was the most variable component in all foods (0,41 to 21,1 g/100 g). Fired beans (Phaseolus vulgaris: variedad pinto) had the highest DF content (9,21 g/100g); as is basis). Sodium among the minerales was also highly variable mainly due to the addition of salt during preparation of foods, except in corn tortillas were salt is not added. In contrast wheat flour tortillas had the highest sodium content of the foods analysed. Fresh white cheese had the highest calcium content (563 mg/100g). The meat group had the highest content of Fe and Zn (2,4-5,4 and 4,2-5,4 mg/100 g respectively). This study has provided information with current analytical techniques of important foods in northwest Mexico that will contribute to food composition tables in Latin America.